There already exist wear-resistant floor coatings based on epoxy resin and constituted by conventional opaque fillers (in particular quartz and silicas) embedded in an epoxy binder and colored by ground-up pigments or by a colored epoxy paste. These conventional coatings are applied in a single coat, are self-smoothing, have a single color which is uniform, and which has a finish which, when new, is semi-gloss (satin), unless it contains a matting agent. Although such a coating may initially be shiny, it subsequently becomes matt by being scratched in use. Its surface may be smooth or structured (if the coating is to be a non-slip coating).
The use of an epoxy resin in a coating provides several advantages: this resin has remarkable chemical inertness and mechanical strength (a hardness of 2 on the Gardner scale), its flammability is low (classification M1 in the building materials fire classification scale of the (French) Scientific and Technical Center for the Construction Industry); when it does burn, it does not give off toxic vapors; it is translucent; and its natural pale amber color allows all sorts of tinting. Some polyurethane resins are hard, translucent, and pale, but they are sensitive to damp (they react with the water contained in the concrete or cement on which they are laid, and the reaction gives off carbon dioxide gas, thereby forming unsightly bubbles in the coating and reducing its adherence). In addition they are flammable (classification M2 or M3) and when they burn they give off highly toxic hydrocyanic acid. The use of epoxy resins is therefore preferred.
There also exist colored decorative coatings based on epoxy resin and grains of colored quartz, known as "Quartzcolor". These grains are relatively large in diameter, they are heavy, and if they are mixed in bulk with the resin they settle out, thereby giving a varying surface appearance to the coating since the thickness of the coating, in particular on concrete, is irregular due to the fact that the surface of a concrete support is not plane, even after it has been prepared. The current technique therefore consists in laying five successive thin coats of epoxy binder on the concrete with each coat having said grains of quartz dusted over it. The coats are applied at one-day intervals. Overall application therefore takes five days. The total thickness of the resulting coating is 1 mm to 1.5 mm. It suffers from the risk of the coats coming unstuck since their adhesion is purely physical, and as a result its resistance to mechanical shock is poor. The grains of quartz may be replaced by flakes of colored polyester. The coating is laid using the same technique, and suffers from the same drawbacks.
Other decorative coatings having a thickness of 1 mm to 2 mm, are laid in a single coat using a mixture of pigment in non-filled epoxy resin (which makes application difficult to control), however the pigments settle out and, on a support with a non-uniform surface (such as concrete), the coating has some zones which are properly pigmented and other zones over depressions in the surface of the concrete which are only slightly colored, thus giving rise to an unsightly appearance after the epoxy binder has polymerized.
The object of the present invention is to remedy the above-mentioned drawbacks of prior coatings by providing a new colored decorative coating which withstands wear, and which, in addition, is both translucent and glittering, which characteristics are maintained during use of the coating, and are not to be found in prior coatings.